The present disclosure relates to an image forming apparatus having a developing device for developing an electrostatic latent image into a toner image.
Conventionally, there is known an image forming apparatus that develops an electrostatic latent image into a toner image and transfers (prints) the toner image onto a paper sheet. This image forming apparatus includes a developing device that supplies toner to the electrostatic latent image so as to develop the electrostatic latent image into a toner image.
The developing device stores toner inside, and the toner inside the developing device is consumed while printing is performed (an amount of toner in the developing device is decreased). Accordingly, the image forming apparatus having the developing device is usually equipped with a container (toner box) for storing supply toner. Furthermore, when toner supply to the developing device is necessary, the toner in the container is supplied to the developing device.
In addition, the developing device is equipped with a toner sensor. A supply screw (toner supply roller) is disposed between the container and the developing device. Furthermore, an amount of toner in the developing device is detected on the basis of an output value of the toner sensor. When an amount of toner in the developing device becomes less than an appropriate value, the supply screw is rotated so that the toner is dropped from the container to the developing device. In this way, the developing device is supplied with the toner.